JPS586822Y2 - Double feed prevention device in paper feed device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a double-feed prevention device in a paper feeding device that sequentially feeds stacked sheets one by one.

Conventionally, as a double feeding prevention device for this type of paper feeding device, a snapper type, a remade feed type, etc. are known.

The one-type snapper has a structure in which a pair of snappers are placed under their own weight at the corners of the paper feed side of the stacked paper, and although double feeding can be prevented to some extent, it is unreliable and has a high possibility of double feeding occurring. At the same time, folds may occur at the leading edge of the paper.The remade feed method has a structure in which a remade member is brought into contact with the stacked paper to prevent double feeding, but thin paper cannot be fed.

If it were to be possible to feed even thin paper, the contact pressure of the feed member would have to be changed, resulting in a troublesome operation.

The present invention was devised in view of the above circumstances, and its purpose is to provide a double-feed prevention device for a paper feeder that can reliably prevent double-feeds and also feed thin paper. .

Embodiments of the present invention will be described below with reference to the drawings.

At a predetermined position of the copying machine main body 10, a pair of drawer rails 2,
A drawer cassette 3 is provided so as to be freely drawn out via the drawer 2.

The paper loading table 4 is attached to the bracket 5 in the drawer cassette 3.
, 6 and a pin 7, and the paper loading table 4 has a bottom wall 4a and a rear wall 4b with an open front (paper feeding direction side). A sheet 8 is loaded on the sheet 4a, and the sheet 8 is urged by a spring 9 to swing clockwise about the pin T, so that the sheet 8 is brought into close contact with the sheet feeder 10.

The paper feed roll 10 is rotatably supported on the copying machine main body 1 by suitable means, and is connected to the paper feed roll 10 by =
A plastic film 13 having a pair of guide plates 11 and a guide 12 in a fixed positional relationship is fixed to the copying machine main body 1.

That is, the pair of guide plates 11 are in contact with both corners 8a, 8a of the upper surface of the leading edge of the paper 8 on the feeding side, and the plastic film 13 is opposed to the leading edge 8b of the paper 8 on the feeding side. The upper end surface 13a is the guide plate 11
are in contact with both sides of the lower surface 11a.

The guide 12 is fixed to the lower end side of the plastic film 13 so that only the upper end side of the plastic film 13 is curved.

Next, the operation will be explained.

When the paper feed roll 10 is rotated, the top paper 8' of the paper 8
is sent forward (arrow A), and its both ends abut against the lower surface 11a of the guide plate 11 and the inner surface 13b of the plastic film 13.

At the same time, the second and subsequent sheets of paper 8'', 8''' are sent forward due to the frictional force (coupling force) between the sheets and come into contact with the inner surface 13b of the plastic film 13.

As a result, the glass film 13 is
As shown in the figure, only the two corners 13c and 13d are curved, and a gap t is created between both sides of the upper end surface 13a and the lower surface 11a of the guide plate 11 (FIG. 3). ' is sent out in the paper feeding direction.

At this time, both corners 8a of the uppermost sheet 8' receive force in a direction perpendicular to the traveling direction of the sheet due to a reaction force when both corners 13c and 13d of the plastic film 13 are bent.
The center portion 8c of the paper 8' curves upward, and travels over the inner surface 13b of the plastic film 13 without coming into contact with it.

On the other hand, the second and subsequent sheets 8'' and 8'' come into contact with the inner surface 13b of the plastic film 13 as described above, but the force with which they are sent out is small (usually % of that of the first sheet). 4), the leading edge of the plastic film 13 is not curved and its advancement is prevented as shown in FIG.

That is, if the buckling force of the paper 8 is stronger than the elastic force of the plastic film 13, the paper 8 is pressed against the plastic film 13, bending the plastic film 13, and causing the paper 8 to bend on both sides of its upper end surface 13a and the lower surface of the guide plate. A gap t is created between the two and 11a.

On the other hand, if the elastic force of the plastic film 13 is stronger than the frictional force between the top sheet 8' and the second sheet 8'', the second sheet 8'' comes into contact with the plastic film 13 and stops at that position.

As a result, only the uppermost sheet 8' is sent out in the feeding direction.

As described above, by determining the thickness and elasticity of the plastic film 13 in consideration of all types of paper that can be used in a copying machine, etc., it is possible to reliably prevent double feeding of the paper 8, and also to prevent thin paper from being fed. The paper loading table 4 is equipped with a lever (not shown) that swings counterclockwise against a spring 9, so that when the paper 8 is pulled out of the machine, The paper loading table 4 is swung counterclockwise using a lever to separate the paper 8 from the paper feed roll 10, and then the drawer cassette 3 is pulled out of the machine along the drawer rail 2.

In the above embodiment, the paper feed roll 10 is brought into close contact with the top surface of the paper 8 to feed the top paper 8', but the paper feed roll 10 is brought into close contact with the bottom surface of the paper 8 to feed the bottom paper 8'. Alternatively, the plastic film 13 may be made of a material other than plastic and have a flexible film shape.

The present invention is as described above, and a film-like member 1 having flexibility is formed by a pair of paper guide members 11 and a strainer of the paper 8.
Both corners of the paper 8 are curved, and a gap is created between the paper guide member 11 and the film-like member 13.
a is allowed to pass through, the central portion of the sheet 8 is curved by the reaction force caused by the curvature of both corners, and the sheet 8 is sent out over the central portion of the film-like member 13.

At this time, since the center portion of the film-like member 13 is not curved and is in an upright state, the second and subsequent sheets can be stopped.

Therefore, the stacked sheets 8 can be reliably fed one by one without double feeding.

Since the film-like member 13 is curved by the straining of the paper 8, even thin paper can be fed reliably without double feeding.

[Brief explanation of drawings]

Fig. 1 is a front view showing an embodiment of the present invention, Fig. 2 is a plan view, and Figs. 3 and 4 are operations of the portions marked ■-■ and rv-iv in Fig. 2 during paper feeding. The explanatory diagram, FIG. 5, is a perspective view at the time of paper feeding. 4 is a paper loading table, 8 is paper, 10 is a paper feeding means, 11 is a paper guide member, and 13 is a film-like member.

Claims (1)

[Scope of utility model registration request] In a paper feeding device in which the paper 8 loaded on the paper loading table 4 is fed one by one by the paper feeding means 10, at both corners 8a, 8a of the uppermost surface or the lowermost surface of the paper 8 on the feeding side. A pair of paper guide members 11 and paper 8 are pressed together.
A sheet feeding device characterized in that a flexible film-like member 13 is provided, which faces the feeding side end surface 8b, has one end surface 13a in contact with the paper guide member 11, and has the other end fixed. Double feed prevention device.